Background: All-inside meniscal repairs are performed with increasing frequency because of the availability of newly developed devices. A comparison of their biomechanical characteristics may aid physicians in selecting a method of meniscal repair.
Hypothesis: All-inside meniscal repairs will be superior to their inside-out controls in response to cyclic loading and load-to-failure testing.
Study Design: Controlled laboratory study.
Methods: Sixty-six bucket-handle tears in matched porcine menisci were repaired using the Ultra FasT-Fix, Meniscal Cinch, Ultrabraid No. 0, and FiberWire 2-0 sutures. Initial displacement, cyclic loading (100, 300, and 500 cycles), and load-to-failure testing were performed. The displacement, response to cyclic loading, and mode of failure were recorded. The stiffness was calculated.
Results: The Meniscal Cinch demonstrated a significantly higher initial displacement than the other methods tested (P = .04). No significant difference was found among the methods in response to cyclic loading. The inside-out FiberWire repair demonstrated the highest load to failure (120.8 ± 23.5 N) and was significantly higher than both the Meniscal Cinch (64.8 ± 24.1 N, P < .001) and the Ultra FasT-Fix (88.3 ± 14.3 N, P = .002). It was not significantly higher than the inside-out Ultrabraid suture repair (98.8 ± 29.2 N). The inside-out FiberWire repair had the highest stiffness (28.7 ± 7.8 N/mm). It was significantly higher than the Meniscal Cinch (18.0 ± 8.8 N/mm, P = .01). The most common mode of failure in all methods was suture failure.
Conclusion: An inside-out suture repair affords surgeons the best overall biomechanical characteristics of the devices tested (initial displacement, response to cyclic loading, and load to failure). For an all-inside repair, the Ultra FasT-Fix reproduces the characteristics of its matched inside-out suture repair more closely than the Meniscal Cinch.
Clinical Relevance: Inside-out sutures and all-inside devices have similar responses to cyclic loading.
Background: Meniscal root tears have attracted increasing interest in recent years. Fixation is an important factor for rehabilitation and avoidance of early failure. Suture fixations have been the most commonly used techniques. The current study aimed to evaluate the maximum failure load of the native meniscal roots (anteromedial, posteromedial, anterolateral, and posterolateral) and of 3 commonly used meniscal root fixation techniques (2 simple stitches, modified Kessler stitch, and loop stitch).
Hypotheses: (1) There will be no difference in maximum failure load between the native meniscal roots. (2) The loop stitch will sustain the greatest maximum load to failure, followed by the modified Kessler stitch and the 2 simple stitches. (3) The maximum failure load of the native meniscal roots will not be restored by the tested fixation methods.
Study Design: Controlled laboratory study.
Methods: The maximum failure load of the 4 human native meniscal roots was evaluated using 64 human meniscal roots. Additionally, the maximum failure load of the 3 fixation techniques was evaluated on 24 meniscal roots: (1) 2 simple stitches, (2) modified Kessler stitch, and (3) loop stitch using a suture shuttle.
Results: The average maximum failure load of the native meniscal roots was 594 ± 241 N (anterolateral: 692 ± 304 N; posterolateral: 648 ± 140 N; anteromedial: 407 ± 180 N; posteromedial: 678 ± 200 N). The anteromedial root was significantly weaker than the posterolateral and posteromedial roots (P = .04 and P = .01, respectively). Regarding fixation techniques, the maximum failure load of the 2 simple stitches was 64.1 ± 22.5 N, the modified Kessler stitch was 142.6 ± 33.3 N, and the loop was 100.9 ± 41.6 N. None of the fixation techniques recreated the strength of the native roots.
Conclusion: The native anterolateral root was the strongest meniscal root, and the anteromedial root was the weakest meniscal root. Regarding primary fixation strength, the modified Kessler stitch was the strongest technique compared with the loop and the 2 simple stitches.
Clinical Relevance: None of our tested fixation methods restored the strength of native meniscal roots. Thus, rehabilitation after meniscal root fixation should proceed cautiously.
Background
Despite the growing popularity of all-inside meniscal repair devices, concerns remain about their fixation strength. It is also unclear which of these devices have the most ideal biomechanical properties.
Purpose
To compare the biomechanical properties of 3 all-inside meniscal repair devices: the Meniscal Cinch, Ultra FAST-FIX, and MaxFire.
Study Design
Controlled laboratory study.
Methods
Twenty-seven human cadaveric menisci (3 groups of 9) were repaired using 3 different meniscal repair devices. The repaired menisci were then subjected to cyclic loading and load-to-failure testing. Gap formation and ultimate load to failure were measured.
Results
Six of the devices failed during cyclic testing, 4 in the MaxFire group (44%), 1 in the Ultra FAST-FIX group (11%), and 1 in the Meniscal Cinch group (11%). After 1 cycle, there was a trend toward larger gap formation in the MaxFire group (3.65 mm) compared with the Meniscal Cinch group (2.12 mm, P = .05). After 100 cycles, group differences were found in gap formation (P = .03), with the MaxFire group exhibiting greater displacement (6.70 mm) than the Ultra FAST-FIX group (3.59 mm). After 500 cycles, group differences in gap formation (Meniscal Cinch, 5.94; Ultra FAST-FIX, 4.74 mm; Max Fire, 7.19 mm) did not reach statistical significance (P = .20). A trend was found toward higher ultimate load to failure in the Ultra FAST-FIX (86.1 N) and Meniscal Cinch (85.3 N) groups compared with the MaxFire group (64.5 N, P = .06). Stiffness was also higher in the Ultra FAST-FIX (25.2 N/mm) and Meniscal Cinch (25.5 N/mm) groups than the MaxFire group (16.3 N/mm, P = .02).
Conclusion
The Meniscal Cinch and Ultra FAST-FIX devices have more desirable biomechanical properties than the MaxFire as demonstrated by higher stiffness and a lower failure rate during cyclic testing.
Clinical Relevance
The Meniscal Cinch and Ultra FAST-FIX devices may be more desirable implants for use during all-inside meniscal repair as they have superior biomechanical properties when compared with the MaxFire device.
